The present invention relates generally to pumps, and more particularly to a pump driven by an engine.
Internal combustion engines utilize one or more fluid pumps that circulate cooling fluid in cooling passages. Often, these pumps are gear-driven for reliability. In recent years, the ratings of engines have been increased, leading to the need for increased pump capacity so that adequate cooling can be accomplished. This increased capacity can be achieved by increasing the driving speed of the pump and/or increasing pump size.
The location and diameter of the pump driving gear, together with the diameter of the driven pump gear, determine the possible mounting location(s) of the pump along the arc of the driving gear. Efforts to increase pump capacity by increasing the gear-driven speed of the pump have proved problematic, in that the space available for the pump is extremely limited. Specifically, pump speed can be increased through a reduction in the diameter of the driven pump gear. However, such a solution requires the pump to be moved toward the engine block to maintain the gear mesh. In some installations, the engine block or other engine components may interfere with the pump body to an extent that such a design solution is not possible.
Centrifugal pumps with radial volutes have been manufactured for many years. An axial volute scroll pump is utilized on a tractor engine manufactured and sold by John Deere under part number RE53538.
In addition, turbochargers have been designed having a divided housing for a turbine. See, for example, U.S. Pat. Nos. 2,444,644 and 3,941,104 and other patents cited during the prosecution of the latter patent. These types of housings have multiple inlets that receive exhaust gases from separate engine cylinders, multiple volute passages that converge into a single main turbine recess and a single outlet. The multiple inlets and volute passages permit the extraction of energy from the exhaust gas flow paths from the cylinders.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
In accordance with one aspect of the present invention, a pump includes a pump housing having an impeller recess therein and a pump outlet. An impeller is disposed in the impeller recess and first and second separate volute passages are disposed in the pump housing in fluid communication between the impeller recess and the pump outlet.
In accordance with a further aspect of the present invention, an engine system includes an engine and a pump operatively coupled to the engine, wherein the pump includes a housing having an impeller recess therein and a pump outlet. An impeller is disposed in the impeller recess and first and second separate volute passages are disposed in the pump housing in fluid communication between the impeller recess and the pump outlet.
In accordance with yet another aspect of the present invention, a method of pumping fluid comprises the steps of providing a pump having a housing wherein the pump housing includes an impeller recess having an impeller therein and a pump outlet and supplying fluid to the impeller recess and motive power to the impeller thereby to induce fluid flow in the impeller recess. The fluid flow is divided into first and second separate flows in the pump housing and the fluid flows are recombined in a convergence passage in the pump housing adjacent the pump outlet.